Printing machines normally include a printing couple which comprises a number of cylinders and rollers such as an impression cylinder, a master cylinder, a blanket cylinder, form rollers, ductor rollers, transfer rollers, regulator rollers, and the like. For instance, an ink fountain conventionally is disposed generally at the rear of the machine for feeding ink to the various rollers of the printing couple which transfers images to copy sheets. In such printing machines as rotary offset lithographic duplicating machines, a moisture fountain also is disposed adjacent the printing couple for feeding moisture to the printing couple. A number of rollers, such as a fountain roller, a pickup roller, a transfer roller and a form roller, which generally can be termed "distribution" rollers, are provided between the moisture fountain and/or ink fountain for distributing moisture and/or ink to the printing couple of the machine.
There generally are two types of moisture and ink distribution systems in printing machines of the character described. One system commonly is called an "integrated" system wherein the moisture and ink are mixed in common paths leading to the master cylinder. The other system commonly is called a "separated" system wherein the moisture and ink are distributed to the master cylinder through separate paths. In the industry, a printing establishment conventionally will determine which system satisfies their needs and obtain and use a machine almost exclusively employing either an integrated system or a separated system. On occasion, it may be desirable to change from one system to the other. In such instances, the establishment either has to obtain a completely new machine which is set up with the other system or perform major overhaul operations on the existing machine to convert from one system to the other. Such conversions are both expensive and time consuming.
This invention is directed to providing a novel conversion apparatus for readily changing the printing couple of a printing, duplicating or like machine between the integrated and separated systems.
Another conversion problem encountered by printing establishments involves the moisture feeding system itself. As stated above, moisture feeding systems conventionally include a number of rollers for distributing moisture to a form roller in rolling contact with the master cylinder. Because of the different diameters of the various rollers and the imprecise gear ratios driving the rollers, there normally is slippage at one point or the other between the rollers of the moisture feeding system. In integrated systems, the slippage conventionally occurs between the transfer roller and the moisture form roller. However, there are certain instances in which a printing establishment may desire to employ a sleeve of fabric or fibrous material over the moisture form roller which engages the master cylinder. This normally is done in a separated system so that ink is not distributed onto the sleeve. The sleeve is provided for absorbing the moisture to constantly retain a residue of moisture in the sleeve which is believed to provide a more stable moisture feeding system. However, when such a sleeve is used, there can be no slippage between the moisture form roller and the adjacent transfer roller because such slippage would cause the sleeve to "bunch".
This invention further is directed to providing a system wherein the driving connection for the transfer roller of the moisture feeding system is convertible to either allow or avoid slippage between the transfer roller and the moisture form roller.